Hi all,
I'm about to tackle the rear now and will be removing the gas tank, leafs, shocks and exhaust system. I plan to do a lot of wire brushing, cutting, welding and shoving. I want to be sure that she's a solid as possible when off the concrete by about 2 feet, so I'll be mainly relying on blocked-up jack stands on the four key points, but want more than just that. Any other good sturdy ideas that have made you more comfortable under there?

To start with, if you put jack stands on top of anything other than sometime bolted down to the floor your gonna die on us. Jack stands on blocks is an easy way to hurt and possibly kill you.

The are good reasons for why jack stands (typical ones you buy at a popular store front) are limited in height. Some of you guys are Engineers and took a Statics course and you the calcs that prove the instability of jack stands given the diameter of the base of the jack stand.

I won't get into the calcs but understand that the higher you go up on a jack stand the more unstable it becomes. The mechanical advantage (lever) increases with height of stand. For example, if you push the car horizontally with a jack stand that is 3' high, it does not require as much force to tip it over. It's like putting a 3 foot metal pipe on the end of you socket wrench.

So if you want to go high you have to purchase much larger stands to handle that height. Stands will be higher (static lowered height) and the base diameter will be much larger. The increased size of the base is what allows you to go higher.

You can do a few things to make the common smaller stands work higher, but it's risky when you are battling with the car.

I will give you some options you can think about.

1st, you can build it in wood or steel. If you know more about wood than steel then consider using wood. Obviously steel could be used as well.

Option #1 Wooden blocks stacted (6" x 6")
Option #2 Wooden or steel cart (lots of plans out there for these. Requires welding for steel but I have a wooden cart that will hold a heavy car shell (no drive trane), easy to build
Option #3 Special steel cart that can be configured to be used by a range of cars. Height, width and length adjustable.
Option #4 Hydraulic hoist to lift car up. Limited on what you can do with this design.

Work smart, do your research in advance (like your doing now). BUY GOOD tools! Tools can make difficult job fun and rewarding. Save money by working smarter and buying good tools. Remember, when your done your project you can sell your tools and recover at least 50% of your investment. I bought a paint gun for $500 US. The quality is amazing. They retail at $1000. How much do you think I could get back for a one car use of a SATA paint gun? You save nothing buying crap. 3 paint guns, one price, products are cash cows for the distributor but useless for you. They are good for a couple of sprays and then they are done. Worth $0! And they suck as far as quality goes.

Get your self 2 good trolley jacks as well. Get them from COSTCO, they go bad 5 years later, you can take em back for refund or get another new one.

I can send you some picks of this stuff. Let me know what your interested in.

One last thing...a guy came onto the forum one day and chatted about how happy he was to be finished removing all the dirt, grease, paint off the underside of the car. He laid under the car with no stands, jack or anything. Used a scrapper, wire brush on a drill. Time is more important than cash. You can get more productivity out a plant increasing the no. people working there (many other things as well). You can go from 20/cars a day to 1000 cars/day. BUT you can't change the work day from 8 hours to 5000 hrs. God only gave us a 8 hr day. If you want more people hours (hr/day x no. of people) then hire more people. Back to our "hero" above; where do you start?

So I'm a little heaving on the spending (my project is stalled awaiting to get more time available to work on my project), try to find a balance you can leave with.

X2

"To start with, if you put jack stands on top of anything other than sometime bolted down to the floor your gonna die on us. Jack stands on blocks is an easy way to hurt and possibly kill you."

Thx Guys.
My preference is to dig a slot in the garage floor and get in it. I guess I just need to get used to it being tight under there when working.... everybody else does it!

Hey how about you just buy a lift and then sell it and take a small loss when you're finished with all the work? Justify it as good life insurance. Hard to put a price on death benefits( although the ins companies seem to be able to decide your worth).

I just did this replacing my rear end and ALL suspension. I bought 2 lengths of 2x4 wood. I used 2 jack stands under the front subframe, then used 2 jack stands with the 2x4 under the rocker panel on each side as far to the rear as possible. The car was sturdy as hell so long as your front jacks are as far forward as you can get them so the back of the car doesn't lift when you remove the axle, springs, etc. I also have a couple of floor jacks I place here and there as insurance.

I'll be doing this again for my T56 swap in just a few weeks.

How I did mine too.
And whenever using stands have couple large diameter oak logs to roll and/or slide under car depending on height.
Also if just using floor jack to change oil have 2 old Rally wheels to slide under a-arms or frame.

OK, retired construction engineer here. I made a similar setup with a couple suggested changes and an option. 1) Use 4x4's instead of 2 x 4's. Not a big cost difference and WAY less flex in the 4 x 4's. And these days, trying to find a 2 x 4 that is actually straight is a challenge.

2) Optional: I mounted my 4 x 4's on HD car skates and then placed screwed down 2 x 4 blocks at the top ends of the 4 x 4's under the front and rear of the rocker panels. You will need clearance for the dips in the floor panels - especially the rear floors. Thus I could actually move the body shell around and "park it" when I was done for the day.

3) One additional caution as anguilla mentioned: Support at the rearmost section of the rocker panels is a bit too close to the tipping point of my setup as shown here but with a full front clip and motor installed. Additional support under the engine or subframe is required.

OK...
So the car will be totally complete when I jack it up for the suspension and exhaust demo and upgrade. I have the Pontiac lift point engineering diagrams showing the correct spots to support/jack it on the main frame and rear body. I wont be removing the rear end, but will be using one of the jacks to support it when I unbolt the springs. I'm figuring that the weight distribution wont be terribly different, less a 150lbs of leafs and shocks out of the rear, so I shouldn't have any tipping issues.
Problem I may have is that the rear support points per GM are very close to the front leaf spring cup-mount-things (tech term). So I'm not sure about my wood block stack plan vs socket wrench...
When I get this set up, I'll revisit this with a picture. It'll be strong, and you'll likely get a good laugh.

Call it redundant, conservative, belt and suspenders or just paranoia, but when I get under a vehicle for even an oil change I use both main and backup supports. I use a combo of supports from a choice of four jack stands, two hydraulic jacks, a van screw-type bottle jack, two ramps and have even used the Firebird's bumper jack as a final backup. The Firebird is so low and I need XL clearance to get under it so that car has to be raised quite a bit.

I use 6 ton stands, they hold the car up 24". When I want to go higher I put them on blocks 4"X16"X16", If I need to go higher I use 6"X16"X16". If the car isn't going to tip with the stands on the floor it isn't going to tip with the stands on the blocks. Probably be a lot easier to tip if the blocks were the same width as the stand. Problem with having the stands on blocks that wide is getting around between the blocks.

Eventually it gets down to who has the biggest blocks. I will show you high baby!

The square steel tube allows you to rest the car on those small support plates and keep the car stable. The wood structure can be built quite high. Just be sure to make base larger as you go higher. Also, consider tacking on 2 longer pieces on the bottom and it gives it more stability.
I have one built with 4" x 4" as well.

I included some pics of the process I used to remove frame from my wagon. Notice how far I can place the wood stands away from car and it remains stable. I just pushed the frame out!

Hahaha!! that's fantastic, Gus...wow.
I'm totally with you Jimc... I really don't like being under there. I'm borderline claustrophobic as it is, so getting under there is a love-hate thing... I actually did look at the cost of a lift, but what I can get in my garage wouldn't get me up much higher that the 24-26" I can get with the 6ton stands on a few blocks. So I'll pray and just get it done. But Gus....Jenga stacks... really? Your guardian angel must be a car guy.

You laugh but that car won't go down. We I moved into our last place I found a set of 2 that someone built with 4"x4"s I created my own with 1" x 3" and 2" x 4" I was able to remove the lower full frame out myself. A look at cost...cheap! I used the same setup to remove rear diff. No jack stands in your way.